Our objects are (1) to determine which neural systems are activated by rewarding brain stimulation; (2) to follow the development of functional barrel field activity in the somato-sensory cortex of the rat; (3) to determine the effect of elevated neural activity on vulnerability to hypoxic damage; (4) to further the development of 2-deoxyglucose autoradiography as a general tool in the neuro-behavioral sciences. Despite the diversity of objectives, 2-DG autoradiography is the principal method of assaying neural activity in all 3 projects, which is why they joined in a single proposal.